1. Field of the Invention
The present invention relates to a filtering pump assembly. More particularly, the present invention relates to a portable pump assembly which includes a filter subassembly with a cage member for surrounding an inlet of a pump subassembly, and a replaceable filter element for covering the cage member.
2. Description of the Background Art
Many different types of portable pumps are known. For example, U.S. Pat. No. 4,741,664 to Olmstead et al. discloses a portable pump that is suitable for pumping a corrosive liquid out of a standard 55 gallon drum. In the pump design of Olmstead, an inner tube is positioned coaxially within an outer tube, and a driven shaft is disposed coaxially inside of the inner tube. The inner tube protects the shaft from being contacted by the liquid being pumped through the intermediate space between the inner and outer tubes. A motor sits atop the assembly for spinning the shaft, and the shaft has an impeller mounted on the lower end thereof.
Another portable pump design, similar to the design of Olmstead, is disclosed in U.S. Pat. No. 4,627,790 to Bowes et al.
Although the known portable pumps are useful for their intended purposes, a need still exists in the art for a pump having the ability to pre-filter the fluid being pumped therethrough to prevent entry of larger impurities thereinto. In particular, a need exists for a pump design in which a filter medium is removable and replaceable.